Just to be pedantic, I'll note the FA had AMP (Automatic multi-pattern) 
metering, matrix metering was introduced on the F801/N8008 (The hardware 
was identical though).

To this day, I find the FA has one of the best meters Nikon's ever 
produced. In testing, I found it to outperform the later 6 segment units 
that Nikon used in the late 90's and early 2000's in the low and 
mid-range bodies. It also performed as well as the 8 segment unit in the 
F90/F90x.

The 16 segment unit in the *ist's and k1x0D seem to be similarly 
accurate, and lack the Nikon 5-segment units one failing, the occasional 
issue with portrait orientation.

-Adam


Godfrey DiGiorgi wrote:
> On Oct 22, 2006, at 8:24 AM, Shel Belinkoff wrote:
>> ...While it might have been nice to know how to make the lenses  
>> provide multi
>> segment metering, I really didn't care very much to waste time  
>> looking for
>> a solution.  Others here are so much better at fiddling around with  
>> such
>> things.  If it were an issue, I'd have just asked the list, and  
>> guys like
>> Roberts would probably have an answer.
>>
>> BTW, isn't matrix metering what Nikon calls their system, and doesn't
>> Pentax use the term "multi segment metering?"  Are the two the  
>> same, or is
>> there some difference between them? ...
> 
> Nikon was the first to market with "matrix metering" in the FA model  
> and I guess the name is theirs, but it's stuck around as being a  
> generic term. Pentax calls it 'multi-segment metering'. Both are  
> implementations of the same idea, which I think is more precisely  
> called "evaluative exposure estimation":
> 
> - Measure the scene at multiple points using independently sensitive  
> zones.
> - Compare the relationships of the zones, weighted appropriately,  
> against a library of scene types to identify known exposure  
> evaluation issues.
> - Take that type analysis plus the total average brightness of the  
> scene, along with the weighted segment values, to produce a good  
> guess at best overall exposure setting.
> 
> For the simple, early generation systems like this, the information  
> required for open aperture metering is max aperture and exposure time  
> aperture setting.
> 
> This can become arbitrarily trickier with more sophisticated  
> information and higher power processing in the metering system.  
> Factors that help aid scene type identification can be focal length  
> and focus setting, factors that help aid exposure setting can be  
> color balance, you can include color information (as Nikon does with  
> RGB matrix metering bodies). These later systems require lenses that  
> provide the relevant additional information for the specific metering  
> system in question.
> 
> Ancient lenses that do not have chips in them to provide this  
> information electronically are not compatible with this metering mode  
> on the Pentax DSLRs no matter what you do, due to the way the  
> implementation was integrated with the rest of the camera's real time  
> control system. (The same is true for Nikon's D200 ... except that  
> they've provided a way to input some of the required data for a  
> specific lens that you mount and enable one of the simpler forms of  
> the metering mode.)
> 
> In my experience, matrix metering evaluations with the Pentax *ist DS  
> resolve to be arbitrarily close to Center Weighted Averaging readings  
> UNLESS I set the option to link the AF and AE point and use the full  
> AF sensor array. Then I see some variations in the selected exposure  
> settings.
> 
> Godfrey
> 


-- 
PDML Pentax-Discuss Mail List
[email protected]
http://pdml.net/mailman/listinfo/pdml_pdml.net

Reply via email to